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authorPaul E. McKenney <paulmck@linux.ibm.com>2018-12-10 09:44:52 -0800
committerPaul E. McKenney <paulmck@linux.ibm.com>2019-01-25 15:37:10 -0800
commit3a6cb58f159e64241b2af9374acad41a70939349 (patch)
treeada940f453392a61ee945b23974647841ee65700 /kernel/torture.c
parent0d8a9ea9764a0e34e17e3b80a2be3855de239d6e (diff)
rcutorture: Add grace period after CPU offline
Beyond a certain point in the CPU-hotplug offline process, timers get stranded on the outgoing CPU, and won't fire until that CPU comes back online, which might well be never. This commit therefore adds a hook in torture_onoff_init() that is invoked from torture_offline(), which rcutorture uses to occasionally wait for a grace period. This should result in failures for RCU implementations that rely on stranded timers eventually firing in the absence of the CPU coming back online. Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Diffstat (limited to 'kernel/torture.c')
-rw-r--r--kernel/torture.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/kernel/torture.c b/kernel/torture.c
index bbf6d473e50c..a03ff722352b 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -75,6 +75,7 @@ static DEFINE_MUTEX(fullstop_mutex);
static struct task_struct *onoff_task;
static long onoff_holdoff;
static long onoff_interval;
+static torture_ofl_func *onoff_f;
static long n_offline_attempts;
static long n_offline_successes;
static unsigned long sum_offline;
@@ -118,6 +119,8 @@ bool torture_offline(int cpu, long *n_offl_attempts, long *n_offl_successes,
pr_alert("%s" TORTURE_FLAG
"torture_onoff task: offlined %d\n",
torture_type, cpu);
+ if (onoff_f)
+ onoff_f();
(*n_offl_successes)++;
delta = jiffies - starttime;
*sum_offl += delta;
@@ -243,11 +246,12 @@ stop:
/*
* Initiate online-offline handling.
*/
-int torture_onoff_init(long ooholdoff, long oointerval)
+int torture_onoff_init(long ooholdoff, long oointerval, torture_ofl_func *f)
{
#ifdef CONFIG_HOTPLUG_CPU
onoff_holdoff = ooholdoff;
onoff_interval = oointerval;
+ onoff_f = f;
if (onoff_interval <= 0)
return 0;
return torture_create_kthread(torture_onoff, NULL, onoff_task);

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